The present invention relates to a commutator in which predetermined commutator pieces are short-circuited, and to an armature.
In the prior art, an armature for a motor having power feeding brushes may include a commutator in which a plurality of commutator pieces are short-circuited. Such a motor allows electric current to flow even to commutator pieces that are not in contact with power feeding brushes by short-circuiting predetermined commutator pieces. This enables a reduction in the number of power feeding brushes required in the motor.
In one example, in a rotation machine described in Japanese Laid-Open Patent Publication No. 2000-134873, short-circuit wires for short-circuiting commutator pieces are arranged on an end portion of a commutator.
However, when the short-circuit wires are arranged on the end portion of the commutator, the short-circuit wires may rub against one another or the short-circuit wires may rub against coils and cause an electric connection (layer short). This would lower yield during the manufacturing of the armature or cause erroneous operation.